CN111324955A - Free-form surface laser cutting method - Google Patents
Free-form surface laser cutting method Download PDFInfo
- Publication number
- CN111324955A CN111324955A CN202010102676.7A CN202010102676A CN111324955A CN 111324955 A CN111324955 A CN 111324955A CN 202010102676 A CN202010102676 A CN 202010102676A CN 111324955 A CN111324955 A CN 111324955A
- Authority
- CN
- China
- Prior art keywords
- edge
- grid
- mesh
- free
- data structure
- Prior art date
- Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
- Granted
Links
Images
Landscapes
- Laser Beam Processing (AREA)
Abstract
A free-form surface laser cutting method belongs to the technical field of laser processing. The invention comprises a method for optimizing the topology of a data structure of a mesh model, which solves the problem of repeated light emission of laser caused by repeated recording of a plurality of common vertexes of a mesh curved surface; a method for topological optimization of geometric information of a grid model solves the problems of grid deformity, opposite methods, common edges, intersection and the like; the method comprises a curved cavity cutting focus track planning rule which can plan the track of a curved cavity. Compared with the prior art, the invention can carry out high-precision direct cutting processing on the free-form surface with large area, high depth, arbitrary curvature and continuous smoothness on the material without the limitation of cutting materials and cutting size. The invention has simple operation and reliable use.
Description
Technical Field
The invention relates to a method for laser cutting of a free-form surface, and belongs to the technical field of laser processing.
Background
The free-form surface refers to a curved surface which has the arbitrary characteristics of traditional processing and forming and the surface shape of which cannot be continuously processed. The product expressed by the free curved surface has high degree of freedom, excellent aerodynamic performance, fluid dynamics performance, thermodynamic performance and the like, and is widely applied to important fields of aviation, automobiles, ships and the like. However, the precision requirement is high and the precise representation by mathematical expressions is difficult, so the free-form surface processing is always a great problem in the processing field of the present day. Traditional free-form surface processing adopts multiaxis linkage digit control machine tool, is equipped with diamond or alloy cutter and mills, because free-form surface's complexity, there are a lot of difficulties in cutter orbit planning, and the programming parameter need be adjusted repeatedly to the course of working, and outside high-cost processing, by the restriction of milling cutter self size, the characteristic dimension that can reach is very limited, often can't satisfy to actual processing demand and yardstick requirement. Meanwhile, the contact type cutter machine has limited cutting objects, and basically cannot be used for hard and brittle materials such as hard alloy, ceramic, monocrystalline silicon and the like which are difficult to machine. The laser cutting can not be limited by a cutter and materials, but the conventional laser cutting processing can not achieve the hardware condition by controlling a laser beam to repeatedly scan the same pattern, one layer of ablation (or stripping) material is used for achieving a certain size requirement, and the free curved surface processing needs to be matched with high-speed or continuously-changed focal plane adjustment. The laser three-dimensional inner carving can form a three-dimensional pattern in the transparent material, the three-dimensional etching pattern is superposed by using laser to etch the detonation point of the material, the material is not effectively removed, the cutting of the planar material is more difficult to realize, and the material is only limited to the transparent material.
Disclosure of Invention
In order to overcome the defects, the invention provides a laser cutting method of a free-form surface, which comprises a data structure topology optimization method of a grid model, a grid model geometric information topology optimization method and a laser focus track generation method.
The grid model used by the method is established by modeling software such as Solidworks, Pro/Engineer and the like and is stored by an STL grid model.
The method for optimizing the topology of the data structure of the grid model is characterized in that each vertex not only contains corresponding three-dimensional coordinate information, but also registers vertex normal vector information; the vertex, the edge and the surface can be directly indexed, and when a certain vertex is read, the corresponding edge and surface information can be directly indexed; when a certain edge or a certain surface is read, the corresponding vertex and the corresponding surface or edge information can be directly indexed, and the same geometric information (the three-dimensional coordinates of the vertex and the common edge of the mesh patch) is only stored once. By the method, the problem of repeated recording of data information of the vertexes, edges and surfaces of the mesh model is solved.
The method for optimizing the geometric information topology of the grid model is characterized in that the chord difference of the grid model is regulated, the number of grid patches is changed, and the problems of grid deformity, opposite methods, common edges, intersection and the like are solved, but the method is not limited to solving the problems. Specifically, let the circumscribed circle radius of the mesh patch T be R, and the shortest side length be LminThen when
The time is the optimal grid quality. However, in practical optimization, both the computer data processing time and the memory consumption need to be considered, and for LminAnd taking values of the ratio of the R to complete the topological optimization of the geometric information of the grid model.
The method for generating the laser focal track is characterized in that the laser focal is controlled in real time, and the focal track generation rule is described as follows:
1) dividing the free-form surface mesh model into a plurality of slices, initializing a state flag F of each edge in an edge table, and setting flags of all edges to be zero, namely F is 0; 2) traversing all edges, finding the grid, P, intersecting the tangent plane1，P2For the intersection of the tangent plane and the grid, P will be satisfied1·z≤Z＜P2Z or P1·z＞Z≥P2Z, the flag of the side of z is set to 1, i.e. F is 1; 3) traversing the edge table, and taking the searched edge with the first F ═ 1 as the starting edge of the slice; 4) establishing a loop chain table for storing the outline intersection points, solving the intersection points of the tangent plane and the initial edge, and adding the intersection points into the table; 5) searching the grid where the edge partner edge is located according to the adjacent edge table, namely the adjacent grid; 6) finding the edge with the mark F equal to 1 in the adjacent grid, firstly judging whether the edge is the initial edge of the ring, if so, indicating that the ring is completely calculated, and turning to 7); otherwise, the intersection point is obtained, the intersection point is added into the linked list of the ring, the mark F of the edge is set to be 0, and then 5) is carried out. 7) Continuing to search the edge table for an edge with F ═ 1, if found, indicating that the starting edge of the next ring is found, and then turning to 4); otherwise, 8) is turned; 8) the layer cut is finished. Increasing a slice layer height, firstly judging whether the whole model is sliced or not, if so, judging whether the whole model is sliced or notTurn 9); otherwise, turning to 2), and continuing to slice the next layer; 9) the slicing is ended.
The method for optimizing the topology of the data structure of the grid model is characterized in that each vertex not only contains corresponding three-dimensional coordinate information, but also registers vertex normal vector information.
The method for optimizing the topology of the data structure of the mesh model is characterized in that vertexes, edges and surfaces can be directly indexed, and when a certain vertex is read, corresponding edge and surface information can be directly indexed.
The method for optimizing the topology of the data structure of the mesh model is characterized in that when a certain edge or a certain surface is read, the information of the corresponding vertex and the corresponding surface or edge can be directly indexed.
The method for optimizing the topology of the data structure of the mesh model is characterized in that the same geometric information (three-dimensional coordinates of a vertex and a common edge of a mesh patch) is only stored once.
The method for optimizing the geometrical information topology of the grid model is characterized in that the chord difference of the grid model is regulated, the number of grid patches is changed, and the problems of grid deformity, opposite laws, common edges, intersection and the like are solved, but the method is not limited to solving the problems.
Suppose that two end points of an edge are respectively P1(x1,y1,z1)、P2(x1,y1,z1) Then the equation of the line of this edge in space:
let the tangent plane equation be z ═ z0And then, the tangent plane coordinates of the intersection point of the two formulas:
the tangent plane is parallel to a certain edge of the mesh and just coincides with the edge or the triangle is equal because the Z coordinates of two end points of the edge are equal, but when Z is1＝z2Then, the coordinates of the intersection cannot be obtained from the above equationActually, the number of the intersection points is infinite solution, the intersection points are solved by the other two sides of the triangle, and the search condition for determining the edge set is set as follows:
P1·z≤Z＜P2z or P1·z＞Z≥P2·z，
The edges where the two end points Z-coordinates are equal are excluded.
Compared with the prior art, the invention can carry out high-precision direct cutting processing on the free-form surface with large area, high depth, arbitrary curvature and continuous smoothness on the material without the limitation of cutting materials and cutting size.
Drawings
FIG. 1 is a parametric model of an illustrative embodiment;
FIG. 2 is a mesh model that is offloaded from a parametric model in an embodiment of the specification;
FIG. 3 is a mesh comparison before and after a data structure topology according to an embodiment of the specification;
FIG. 4 is a comparison of mesh models before and after topology of geometric information according to embodiments of the specification;
FIG. 5 illustrates a free-form cutting laser focal track for an illustrative embodiment;
FIG. 6 shows the cutting results of the free curved surface of the alumina ceramic according to the examples.
Detailed Description
In order to make the objects, technical solutions and advantages of the embodiments of the present invention clearer, the technical solutions in the embodiments of the present invention will be clearly and completely described below with reference to the drawings in the embodiments of the present invention, and it is obvious that the described embodiments are some, but not all, embodiments of the present invention. All other embodiments, which can be obtained by a person skilled in the art without any inventive step based on the embodiments of the present invention, are within the scope of the present invention.
Example (b):
the cutting material selected by the invention is alumina ceramic, the used laser is a nanosecond laser, and the complete free-form surface laser cutting process comprises the following steps:
(1) establishing a free-form surface parameter model as shown in FIG. 1, and storing the free-form surface parameter model by using an STL mesh model as shown in FIG. 2;
(2) carrying out topology optimization on a data structure of the grid model, wherein each vertex of the grid model after topology not only comprises corresponding three-dimensional coordinate information, but also registers vertex normal vector information calculated by an algorithm; the vertex, the edge and the surface can be directly indexed, and when a certain vertex is read, the corresponding edge and surface information can be directly indexed; when a certain edge or a certain surface is read, the corresponding vertex and surface or edge information can be directly indexed. The mesh topology front-back point, edge, face-to-face is shown in figure 3.
(3) Carrying out topology optimization on the geometric information of the grid model, namely regulating and controlling the chord difference of the grid model, the embodiment adopts
The ratio of (3) is used for carrying out geometric information optimization on the grid model, and solving the problems of grid deformity, opposite methods, common edges, intersection and the like. The mesh model after geometric information topology optimization is shown in fig. 4.
(4) The track generation method comprises the following steps: 1) 2), … … 8), 9) to generate a free-form laser cutting focal track, the laser focal tracks of layers 1, 10, 18, and 27 are as shown in fig. 5.
(5) And (3) finishing the cutting of the free curved surface of the alumina ceramic by using nanosecond laser on the model after the topology optimization and adopting the focal track in the step (5), wherein the cutting processing result is shown in fig. 6.
Claims (6)
1. A free-form surface laser cutting processing method is characterized by comprising a data structure topology optimization method of a grid model, a geometric information topology optimization method of the grid model and a laser focus track generation method;
the method for generating the laser focal track specifically comprises the following steps:
1) dividing the free-form surface mesh model into a plurality of slices, initializing a state flag F of each edge in an edge table, and setting flags of all edges to be zero, namely F is 0;
2) traversing all edges, finding the grid, P, intersecting the tangent plane1，P2To be cut flatThe intersection of the plane and the grid will satisfy P1·z≤Z＜P2Z or P1·z＞Z≥P2Z, the flag of the side of z is set to 1, i.e. F is 1;
3) traversing the edge table, and taking the searched edge with the first F ═ 1 as the starting edge of the slice;
4) establishing a loop chain table for storing the outline intersection points, solving the intersection points of the tangent plane and the initial edge, and adding the intersection points into the table;
5) searching the grid where the edge partner edge is located according to the adjacent edge table, namely the adjacent grid;
6) finding the edge with the mark F equal to 1 in the adjacent grid, firstly judging whether the edge is the initial edge of the ring, if so, indicating that the ring is completely calculated, and turning to 7); otherwise, solving the intersection point, adding the intersection point into the linked list of the ring, setting the mark F of the edge as 0, and then turning to 5);
7) continuing to search the edge table for an edge with F ═ 1, if found, indicating that the starting edge of the next ring is found, and then turning to 4); otherwise, 8) is turned;
8) finishing the layer slicing; increasing a slice layer height, firstly judging whether the whole model is sliced or not, and if so, turning to 9); otherwise, turning to 2), and continuing to slice the next layer;
9) the slicing is ended.
2. The method of claim 1, wherein in the mesh model data structure topology optimization method, each vertex not only contains corresponding three-dimensional coordinate information, but also registers vertex normal vector information.
3. The method of claim 1, wherein in the topology optimization method for mesh model data structure, the vertices, edges, and faces can be directly indexed to each other, and when a vertex is read, the corresponding edge and face information is directly indexed.
4. The method of claim 1, wherein in the mesh model data structure topology optimization method, information of a vertex and a face or an edge corresponding to a certain edge or a certain face is directly indexed.
5. The method of claim 1, wherein the mesh model data structure topology optimization method stores the same geometric information only once.
6. The method of claim 1, wherein the geometric information flutter optimization method for the mesh model is characterized in that chord differences of the mesh model are regulated, the number of mesh patches is changed, and mesh deformity, opposite law, common edge and intersection are solved.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN202010102676.7A CN111324955B (en) | 2020-02-19 | 2020-02-19 | Free-form surface laser cutting processing method |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN202010102676.7A CN111324955B (en) | 2020-02-19 | 2020-02-19 | Free-form surface laser cutting processing method |
Publications (2)
| Publication Number | Publication Date |
|---|---|
| CN111324955A true CN111324955A (en) | 2020-06-23 |
| CN111324955B CN111324955B (en) | 2023-10-10 |
Family
ID=71171245
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CN202010102676.7A Active CN111324955B (en) | 2020-02-19 | 2020-02-19 | Free-form surface laser cutting processing method |
Country Status (1)
| Country | Link |
|---|---|
| CN (1) | CN111324955B (en) |
Cited By (3)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN112705856A (en) * | 2020-12-30 | 2021-04-27 | 浙江大学 | Three-dimensional model analysis planning method, device and equipment suitable for double-beam laser direct writing |
| CN113642062A (en) * | 2021-10-18 | 2021-11-12 | 广州中望龙腾软件股份有限公司 | Topological geometric data representation method of three-dimensional model, terminal and storage medium |
| CN114309926A (en) * | 2022-03-15 | 2022-04-12 | 北京金橙子科技股份有限公司 | Three-dimensional complex surface-oriented laser marking method and system |
Citations (3)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN1849608A (en) * | 2003-07-16 | 2006-10-18 | 独立行政法人理化学研究所 | Method and program for generating volume data from boundary representation data |
| CN103366069A (en) * | 2013-07-31 | 2013-10-23 | 济南大学 | Hierarchical algorithm of selective laser sintering |
| CN107099797A (en) * | 2017-06-18 | 2017-08-29 | 新疆开源重工机械有限责任公司 | The quick method for planning track of curved surface laser melting coating based on point cloud model |
-
2020
- 2020-02-19 CN CN202010102676.7A patent/CN111324955B/en active Active
Patent Citations (3)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN1849608A (en) * | 2003-07-16 | 2006-10-18 | 独立行政法人理化学研究所 | Method and program for generating volume data from boundary representation data |
| CN103366069A (en) * | 2013-07-31 | 2013-10-23 | 济南大学 | Hierarchical algorithm of selective laser sintering |
| CN107099797A (en) * | 2017-06-18 | 2017-08-29 | 新疆开源重工机械有限责任公司 | The quick method for planning track of curved surface laser melting coating based on point cloud model |
Non-Patent Citations (2)
| Title |
|---|
| 刘金朵;孙文磊;黄勇;黄海博;: "曲面零件激光熔覆轨迹的快速算法与自动生成", 表面技术, no. 09 * |
| 董玲;杨洗陈;张海明;雷凯;: "自由曲面破损零件激光再制造修复路径生成", 中国激光, no. 07 * |
Cited By (5)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN112705856A (en) * | 2020-12-30 | 2021-04-27 | 浙江大学 | Three-dimensional model analysis planning method, device and equipment suitable for double-beam laser direct writing |
| CN112705856B (en) * | 2020-12-30 | 2021-09-21 | 浙江大学 | Three-dimensional model analysis planning method, device and equipment suitable for double-beam laser direct writing |
| CN113642062A (en) * | 2021-10-18 | 2021-11-12 | 广州中望龙腾软件股份有限公司 | Topological geometric data representation method of three-dimensional model, terminal and storage medium |
| CN113642062B (en) * | 2021-10-18 | 2022-03-15 | 广州中望龙腾软件股份有限公司 | Topological geometric data representation method of three-dimensional model, terminal and storage medium |
| CN114309926A (en) * | 2022-03-15 | 2022-04-12 | 北京金橙子科技股份有限公司 | Three-dimensional complex surface-oriented laser marking method and system |
Also Published As
| Publication number | Publication date |
|---|---|
| CN111324955B (en) | 2023-10-10 |
Similar Documents
| Publication | Publication Date | Title |
|---|---|---|
| CN111324955B (en) | Free-form surface laser cutting processing method | |
| CN110555285B (en) | Full-automatic generation method for surface structure grid of complex aircraft | |
| CN112439601B (en) | Spraying robot automatic trajectory planning method for outer vertical surface of large ship | |
| CN108595858A (en) | Lightweight advanced treating working method based on BIM | |
| CN102357666B (en) | Three-coordinate end milling method for blade with freeform surface by using flat-bottomed cutter | |
| Sun et al. | Operation decomposition for freeform surface features in process planning | |
| CN109597354B (en) | Multi-constraint numerical control machining track generation method of triangular mesh model | |
| Xu et al. | A mapping-based approach to eliminating self-intersection of offset paths on mesh surfaces for CNC machining | |
| CN109910180B (en) | Sawing method for rough machining of three-dimensional special-shaped stone by using circular saw | |
| CN108327287A (en) | A kind of rapid generation of three periods minimal surface 3 D-printing slicing profile | |
| CN112613150B (en) | Image expression method of cutting geometry | |
| Ren et al. | Clean-up tool path generation by contraction tool method for machining complex polyhedral models | |
| CN109343468A (en) | A kind of blade multiaxis orbit generation method based on projection biasing | |
| Patel et al. | Optimal tool shape selection based on surface geometry for three-axis CNC machining | |
| CN113721544A (en) | Laser cutting punching-free processing path generation method | |
| KR102020244B1 (en) | A product formed multidirectional latent images and Manufacturing Method | |
| CN110308702A (en) | Three axis constant scallop-height numerical control machining knife rail generating method of point cloud model | |
| Chui et al. | Direct tool-path generation from massive point input | |
| Hu et al. | Boundary-conformed tool path generation based on global reparametrization | |
| Tsainis et al. | A novel convex hull method for optimum multi-point 5-axis tool positioning for machining of complex sculptured surfaces | |
| Chuang et al. | Rough cut tool path planning for B-spline surfaces using convex hull boxes | |
| Duvedi et al. | Drop and tilt method of five-axis tool positioning for tensor product surfaces | |
| CN111666674B (en) | Method for calculating minimum size of cavity channel | |
| CN111597646B (en) | Method and system for intersection of tool and workpiece curved surface in five-axis milling | |
| CN116342849B (en) | Method for generating dental model undercut region on three-dimensional grid |
Legal Events
| Date | Code | Title | Description |
|---|---|---|---|
| PB01 | Publication | ||
| PB01 | Publication | ||
| SE01 | Entry into force of request for substantive examination | ||
| SE01 | Entry into force of request for substantive examination | ||
| GR01 | Patent grant | ||
| GR01 | Patent grant |